Method For Differentiating Driver Input

ABSTRACT

A method for distinguishing intentional steering movements of a driver for influencing an intentional driving path of a motor vehicle from corrective steering movements of the driver as a reaction to unexpected deviations of the motor vehicle from the intentional driving path including ascertaining an instantaneous undisturbed motion of the vehicle along the driving path and calculating a reference value for a steering angle (SAR) corresponding to the ascertained, undisturbed motion of the motor vehicle or a reference value for a steering velocity (SVR) corresponding to the ascertained, undisturbed motion of the motor vehicle. Comparing the reference value(s) (SAR; SVR) with instantaneous steering-angle values (SA(t)) or instantaneous steering-velocity values (SV(t)) and ascertaining whether a difference between the instantaneous steering-angle value (SA(t)) and the corresponding reference steering-angle value (SAR) or a difference between the instantaneous steering-velocity value (SV(t)) and the corresponding reference steering-velocity value (SVR) exceeds a predetermined error-limit value (ΔE) which is established for the calculation of the reference values (SVR; SAR). If so, determining it is a corrective steering movement of the driver as a reaction to an unexpected deviation of the motor vehicle from the intentional driving path.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable.

BACKGROUND OF THE INVENTION 1. Field of the Invention

A method for distinguishing intentional steering movements of a driverfor influencing an intentional driving path of a motor vehicle fromcorrective steering movements of the driver as a reaction to unexpecteddeviations of the motor vehicle from the intentional driving path.

2. Description of Related Art

Modern vehicles are provided with actuators which, in principle, supportdriver input, including operating movements and/or operating forces, orintervene in a supportive manner to assist the driver with vehicleoperation.

In certain operational situations of a vehicle, for example, braking ona roadway having varying coefficients of friction, during a brakingoperation the vehicle undertakes an unintentional and unexpecteddeviation from the intentional driving path. Such deviations caused inpart by pavements having varying coefficients of friction, for example,a roadway that is damp or wet on one side or, for example, in the caseof a roadway frozen on one side. In principle, any driving situation isaffected in which the wheels on one side of the vehicle have africtional contact with the roadway that differs regarding thecoefficient of friction μ from the roadway contact of the wheels on theother side of the vehicle.

When a vehicle decelerates on a roadway surface having differentcoefficients of friction on each side of the vehicle, a yawing moment ortorque about the vertical axis of the vehicle, arises because ofdiffering magnitudes of the braking forces generated on the right andleft sides of the vehicle. Such a yawing moment gives rise to a vehiclemotion, in particular, yawing or turning of the vehicle, toward thatside of the roadway surface having a higher coefficient of frictioncompared to the other side of the roadway surface.

Because the vehicle yaws or turns it departs from the driving pathintended by the driver in an unexpected and often unintentional manner.To compensate for such a yawing or turning of the vehicle, the driverreacts by turning the steering wheel to steer the vehicle in theopposite direction, as a reaction to the yawing motion of the vehicle,to return the vehicle back to the intentional driving path.

These countersteering operations of the vehicle often happen in areflex-like manner and consequently very quickly. Particularly, withexperienced drivers. However, in such a situation the current steeringdoes not match the intended and intentional driving path on which thevehicle should move without the influence of the yawing moment.

In such a case, a conventional driver-support system, designed tosupport driver input, such as the operating movements or operatingforces of the driver, brings about a countersteering support, which, maylead to excessive countersteering, potentially creating an oversteersituation.

With existing steering-assistance systems it may be difficult todistinguish the steering movements of the driver; specifically, whetherthe intended steering movements of the driver are for the intendedinfluencing of the driving path of the vehicle, or whether they are,where appropriate, reactive or reflex-like countersteering movements inorder to bring the vehicle, turning or swinging out or threatening toswing out, back to the intentional driving path. The steering velocitymay be an unsuitable criterion, because with an evasive maneuver, forexample, swerving in relation to an obstacle suddenly arising, such asan animal on the roadway, it is also necessary to perform very fast andreflex-like steering movements. Such an evasive steering movement leadsto an intentional alteration of the driving path, namely around thesuddenly appearing obstacle. In the course of such fast steeringmovements occurring in the manner described above, it is desired, whereappropriate, that a support by the steering-assistance orsteering-support system of the vehicle takes place.

In order to provide a correct intervention of the steering supportsystem, it is necessary to distinguish reflex-like countersteeringmovements from intentional, fast steering movements. Such a distinctionis difficult for existing systems.

SUMMARY OF THE INVENTION

A method for differentiating driver input including determining aninstantaneous non-perturbation vehicle state on an intentional drivingpath and calculating a steering signal reference value based on thenon-perturbation vehicle state. The method compares the steering signalreference value with an instantaneous steering signal value to determineany difference between the two. When the difference exceeds apredetermined value a determination is made that the driver input is areaction to an unexpected deviation from the intentional driving path.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a schematic flow chart showing a first embodiment of themethod according to the invention;

FIG. 2 is a schematic flow chart showing a second embodiment of themethod according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

FIG. 1 illustrates a first embodiment of the invention schematically.The method starts with step 10 and moves to step 20 wherein based onvehicle operating parameters the method determines an undisturbedvehicle motion, course, or state. The undisturbed vehicle state alsoincludes or may be described as a non-perturbation vehicle state,wherein the term perturbation is a disturbance of motion, course,arrangement, or state of equilibrium. While the vehicle is operatingwith an undisturbed vehicle motion, course or state, the method, as partof steps 30, 40 determines or ascertains a reference value,corresponding to the undisturbed vehicle motion, for a steering angleSAR and for the steering velocity SVR.

“Steering angle SA” is the angle, starting from an initial position, thesteering wheel of a vehicle rotates about its steering axis. Thesteering angle SA may also be a lock angle of a wheel the latter has incomparison with the straight-ahead position. In each instance, the timederivative of aforementioned quantities for the steering angle is to beunderstood as the steering velocity. The “steering velocity SV” is theangular velocity of the steering wheel or of a wheel of the wheelsuspension system of the vehicle.

Consequently, a reference value for the steering angle SAR or areference value for a steering velocity SVR available, individually orat the same time. These quantities are representative of an undisturbedvehicle motion traveling along a driving path of the vehicle.Furthermore, in steps 50, 60 the current steering angle SA(t) and alsothe current steering velocity SV(t) are constantly determined orascertained. The ascertainment of the reference values is undertakenusing an inverse vehicle model, in which connecting the associatedsteering angles and steering velocities can be inferred from theundisturbed or no-perturbation vehicle motion. With an inverse vehiclemodel, the equations are inverted wherein a response quantity isspecified as an input and a new set of equations is solved yielding thesteer angle required as an output. The equations provide an input steerangle needed to perform a specific maneuver for various vehicles.

As part of steps 30, 40 the steering-angle reference value SAR orsteering-velocity reference value SVR is provided in each instance withan error-tolerance value ΔE. Next in steps 70, 80 the reference valuefor the steering angle SAR or a reference value for a steering velocitySVR along with the respective error tolerances ΔE are compared to thecurrent steering angle SA(t) or of the current steering velocity SV(t)from steps 50, 60. If the current steering angle SA(t) or the currentsteering velocity SV(t) lie outside a range predetermined by theerror-tolerance value ΔE, it is decided, in the case of a steeringmovement currently being performed by the driver and the steering angleSA(t) and the steering velocity SV(t) resulting from the steeringmovement performed by the driver, it is a corrective movement that doesnot match the undisturbed vehicle motion.

If so, the method moves to steps 90, 100 and a corrective movement ormotion is positively detected, and in step 110 an actuator provided fornormal operation of a motor vehicle for example, typically for furtherundisturbed motion of the vehicle along the intended driving path, isdisabled. Alternatively, an actuator provided for disturbed operationmay be activated.

If the current steering angle SA(t) and the current steering velocitySV(t) from steps 50, 60 are located within the respectively establishedranges for the error-tolerance value ΔE, steps 70, 80, an undisturbedvehicle motion remains, in which case the actuator for undisturbedvehicle operation remains active. As shown with the embodiment of FIG.1, it is sufficient if either the steering angle SA(t) or the steeringvelocity SV(t) lie outside the error-tolerance range ΔE in order tooutput a definition wherein a corrective movement or motion is obtainedand the movement consequently leads, where appropriate, to the disablingof the actuator. In an alternative embodiment it may be that thedefinition of a corrective movement of the driver is output only whenboth the instantaneous steering angle SA(t) and the instantaneoussteering velocity SV(t) exceed the associated limiting values of theerror tolerance ΔE. In such a case, in contrast to FIG. 1, the twoconditions would accordingly have to occur cumulatively. Such aconfiguration also lies within the scope of the invention.

FIG. 2 shows another exemplary embodiment of the invention, wherein thereference values for the steering angle SAR or for the steering velocitySVR are supplemented based on a certain permissible bandwidth for thesteering angle ΔSA or for the steering velocity ΔSV. The bandwidths forthe steering angle, the steering velocity ΔSA, or ΔSV are established insuch a way they cover all possible steering movements and/or steeringvelocities that lead to an undisturbed vehicle motion or are conceivablefor an undisturbed vehicle motion.

In this embodiment the current steering angle SA(t) or the currentsteering velocity SV(t) are compared with the predefined bandwidths ΔSAand ΔSV, respectively in steps 75, 85. If the current steering angleSA(t) lies outside the bandwidth of permissible steering angles ΔSA, orthe steering velocity SV(t) lies outside the bandwidth ΔSV, it is acorrective movement. On the basis of this decision, an actuator is thendisabled, for example, in normal operation of the vehicle, the case ofundisturbed vehicle motion, the actuator supports the steering movementof the driver. Alternatively, an actuator can be activated via adriver-assistance device that has been designed especially for disturbedor perturbation vehicle state.

In comparison with the first embodiment of the invention, the additionalpredefined bandwidths ΔSA and ΔSV are taken into consideration, over andabove the error tolerance ΔE in connection with the ascertainment of theinstantaneous driving path, whereby further possible alterations of thecurrent steering velocity SV(t) or of the current steering angle SA(t)may occur that still pertain to normal operation of the vehicle and donot yet represent an unexpected deviation of the motor vehicle from theintentional driving path. In the course of the ascertainment ofbandwidths ΔSA and ΔSV it can, for example, be taken into considerationthat, where appropriate, on the left and right sides of the vehiclediffering tire pressure is present which, in comparison with theascertained reference value SAR and SVR, may lead to deviatinginstantaneous steering angles SA(t) and steering velocities SV(t)without this being attributable to a calculation error or uncertaintyerror in the ascertainment of the intentional driving path.

The method consequently takes into consideration at least one errortolerance ΔE in the ascertainment of the desired and intentional drivingpath of the vehicle. In addition, in an exemplary embodiment of theinvention an extended bandwidth range for the steering angle ΔSA and forthe steering velocity ΔSV can also be established, which take intoconsideration other irregularities of the vehicle and/or of the drivingsituation that cannot be captured with the model-based or inversevehicle model computational determination of the intentional drivingpath.

The reference values for the steering angle SAR, and for the steeringvelocity SVR, use vehicle operation signals ascertained by sensorsalready present in the vehicle that are used with other systems. Suchsignals may be, for example, associated with one or more of the vehiclestates ascertained by existing vehicle sensors such as: longitudinalacceleration of the vehicle along its longitudinal axis; transverseacceleration of the vehicle along a transverse axis of the vehicle;vertical acceleration of the vehicle along a vertical axis of thevehicle; longitudinal velocity; transverse velocity; vertical velocity;yaw velocity; sway velocity; roll velocity; yaw acceleration; swayacceleration; roll acceleration; and wheel speeds and/or wheelaccelerations of individual wheels or of several wheels of the motorvehicle.

The values of the instantaneous steering angle SA(t) and/or of theinstantaneous steering velocity SV(t) may be obtained from steeringsensors or steering-angle sensors used to ascertain a steering angle SAor a steering velocity SV of the steering wheel about the steering axisthereof or the corresponding angles/speeds in respect of a wheel to besteered.

The disclosed method makes it possible to distinguish, in anadvantageous manner, between a steering movement intended by the driverfor the purpose of altering a desired driving path, and steeringmovements arising as a reaction to an unintentional alteration of thedriving path of the vehicle. An essential distinction for assistancesystems, such as a steering actuator, that are disabled upon detectionof a countersteering movement, often occurring quickly and in areflex-like manner, or for enabling or activating actuators speciallydesigned for special driving situations.

Accordingly, the method distinguishes intentional steering movements ofa driver for influencing an intentional driving path of a motor vehiclefrom corrective steering movements of the driver as a reaction tounexpected deviations of the vehicle from the intentional driving path,the method making it possible to drive the steering-support systemreliably and in a manner supporting the driver, as can be expected bythe latter.

The method first ascertains an instantaneous, undisturbed motion of thevehicle along the intentional driving path. Afterward, in a first aspectof the invention at least one reference value for a steering anglecorresponding to the ascertained, undisturbed motion of the motorvehicle or a reference value for a steering velocity corresponding tothe ascertained, undisturbed motion of the motor vehicle is determined,the aforementioned determination undertaken using an inverse vehiclemodel. The reference value compared with instantaneous steering anglevalues or with instantaneous steering-velocity values.

The method ascertains whether a difference between the instantaneoussteering-angle value and the corresponding reference steering-anglevalue or a difference between the instantaneous steering-velocity valueand the corresponding reference steering-velocity value exceeds apredetermined error-limit value which, for example, is established inadvance for the reference values obtained from the determination orcalculation using an inverse vehicle model. If so, it is determined itis a question of a corrective steering movement of the driver as areaction to an unexpected deviation of the motor vehicle from theintentional driving path.

If such, the intervention of an actuator, for example, a steering-aidactuator for normal operation, can be prohibited straightaway. Whendetermined or ascertained that it is not a question of a correctivesteering movement, in particular, not a reflex-like corrective steeringmovement of the driver, support of the steering actuator can bemaintained or can be triggered and performed.

In one embodiment of the invention, after the ascertaining aninstantaneous undisturbed motion of the vehicle along a driving path, inaddition to the error-limit values, a definition is made that relates topredetermined bandwidths for absolute values of an instantaneoussteering-angle value or to predetermined bandwidths for absolute valuesof an instantaneous steering-velocity value.

Furthermore, it is subsequently ascertained whether the absolute valuesof the instantaneous steering-angle value or of the instantaneoussteering-velocity value lie outside the respectively corresponding,predetermined bandwidth, and if so, deciding that it is a question of acorrective steering movement, in particular a reflex-like correctivesteering movement of the driver as a reaction to an unexpected deviationof the motor vehicle from the intentional driving path. In this case,where appropriate the supportive action of a steering actuator can thenbe prohibited or can be adapted appropriately to the driving situation.

In an exemplary embodiment of the method according to the invention, atleast one driving-assistance system is deactivated if a correctivesteering movement of the driver as a reaction to unexpected deviationsof the motor vehicle from the intentional driving path is detected. Thedriver-assistance system may be, for example, a steering actuator and/ora brake actuator.

In another exemplary embodiment, input signals for the calculation ofthe reference value based on the at least one signal are calculatedbased on at least one state of the motor vehicle selected from thefollowing group: longitudinal acceleration of the vehicle along itslongitudinal axis; transverse acceleration of the vehicle along atransverse axis of the vehicle; vertical acceleration of the vehiclealong a vertical axis of the vehicle; longitudinal velocity; transversevelocity; vertical velocity; yaw velocity; sway velocity; roll velocity;yaw acceleration; sway acceleration; roll acceleration; wheel speedsand/or wheel accelerations of individual wheels or of several wheels ofthe motor vehicle.

In another embodiment, a driver-assistance system can be activated acorrective steering movement of the driver as a reaction to unexpecteddeviations of the motor vehicle from the desired driving path isdetected. Accordingly, where appropriate the driver can be positivelysupported in a critical driving situation as regards actions to beperformed on the vehicle.

Such a driver-assistance system may be, for example, a driver-assistancesystem that is an assistance system for countersteering. Such adriving-assistance system for countersteering supports the driver inreacting to unexpected deviations of the motor vehicle from the desireddriving path, the vehicle being guided further on the desired drivingpath or guided back to the desired driving path.

In another embodiment of the method, a plurality of reference values forthe steering angle and/or for the steering velocity are stored, and ineach instance a temporally last value of the reference value relating tothe steering angle or to the steering velocity that matches anundisturbed driving path of the motor vehicle is used as reference valuefor the comparison with the instantaneous values of the steering angleor of the steering velocity.

With a temporally progressing and continual joint storage of valuesrelating to the steering angle and/or to the steering velocity, it ispossible in a straightforward manner to detect the last drivingsituation in which the steering angle and the steering velocity matchthe desired driving path, and consequently to establish it as a basisfor comparison; that is reference values for the exemplary method.

In another embodiment, a determination of the values of theinstantaneous steering angle and/or of the instantaneous steeringvelocity is undertaken as a function of at least one vehicle state, thevehicle state being selected from at least one of the groups listed inthe following: wheel speeds and/or wheel accelerations of individualwheels or of several wheels of the motor vehicle; position of thesteering wheel or of the steering column, which is ascertained by asteering sensor; angular velocity of the steering wheel about thesteering axis of the steering column; position of at least one steeringwheel with respect to the steering angle.

The description of the invention is merely exemplary in nature and,thus, variations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

What is claimed is:
 1. A method for distinguishing intentional steeringmovements of a driver for influencing an intentional driving path of amotor vehicle from corrective steering movements of the driver as areaction to unexpected deviations of the motor vehicle from theintentional driving path comprising the following steps: ascertaining aninstantaneous undisturbed motion of the vehicle along the intentionaldriving path; calculating a reference value using an inverse vehiclemodel for a steering angle (SAR) corresponding to the ascertained,undisturbed motion of the motor vehicle or for a steering velocity (SVR)corresponding to the ascertained, undisturbed motion of the motorvehicle; comparing the reference value with an instantaneoussteering-angle value (SA(t)) or an instantaneous steering-velocity value(SV(t)); determining whether a difference between the instantaneoussteering-angle value (SA(t)) and the corresponding referencesteering-angle value (SAR) or between the instantaneoussteering-velocity value (SV(t)) and the corresponding referencesteering-velocity value (SVR) exceeds a predetermined error-limit value(ΔE) established for the calculation of the reference values (SVR; SAR);and based on the difference exceeding the predetermined error-limitvalue (ΔE) determining the corrective steering movement of the driver asa reaction to an unexpected deviation of the motor vehicle from theintentional driving path.
 2. The method of claim 1 includingestablishing predetermined bandwidths (ΔSA; ΔSV) for absolute values ofan instantaneous steering-angle value or an instantaneoussteering-velocity value; determining whether the absolute values (SA(t))of the instantaneous steering-angle value or the instantaneoussteering-velocity value (SV(t)) lie outside the respectivelycorresponding, predetermined bandwidth (ΔSA; ΔSV); and based on theabsolute value lying outside the predetermined bandwidth (ΔSA; ΔSV)determining the corrective steering movement of the driver as a reactionto an unexpected deviation of the motor vehicle from the intentionaldriving path.
 3. The method of claim 1 wherein at least onedriver-assistance system is deactivated upon determination of acorrective steering movement of the driver as a reaction to unexpecteddeviations of the motor vehicle from the desired driving path.
 4. Themethod of claim 3 wherein the driver-assistance system is a steeringactuator or a brake actuator.
 5. The method of claim 1 wherein inputsignals for the calculation of the reference value (SAR; SVR) includeone signal representing a state of the motor vehicle selected from thefollowing group: longitudinal acceleration of the vehicle along itslongitudinal axis; transverse acceleration of the vehicle along atransverse axis of the vehicle; vertical acceleration of the vehiclealong a vertical axis of the vehicle; longitudinal velocity; transversevelocity; vertical velocity; yaw velocity; sway velocity; roll velocity;yaw acceleration; sway acceleration; roll acceleration; wheel speeds;and wheel accelerations of individual wheels or of several wheels of themotor vehicle.
 6. The method of claim 1 including activation of adriver-assistance system upon detection of a corrective steeringmovement of the driver as a reaction to unexpected deviations of themotor vehicle from the desired driving path.
 7. The method of claim 6wherein the driver-assistance system is a countersteering assistancesystem supporting driver reaction to unexpected deviations of the motorvehicle from the desired driving path with the vehicle being guided onthe desired driving path or back to the desired driving path.
 8. Themethod of claim 1 including a plurality of stored reference values forthe steering angle (SAR) or the steering velocity (SVR); using atemporally last value of the reference value relating to the steeringangle (SAR) or the steering velocity (SVR) that matches an undisturbeddriving path of the motor vehicle as reference value for the comparisonwith the instantaneous values of the steering angle ((SA(t)) or of thesteering velocity (SV(t)).
 9. The method of claim 1 includingundertaking a determination of the values of the instantaneous steeringangle (SA(t)) or the instantaneous steering velocity (SV(t)) based on avehicle state selected from the following group: wheel speeds and/orwheel accelerations of individual wheels or several wheels of the motorvehicle; position of the steering wheel or the steering column,ascertained by a steering sensor, angular velocity of the steering wheelabout the steering axis of the steering column; and position of at leastone steering wheel with respect to the steering angle.
 10. A method fordifferentiating driver input comprising: determining an instantaneousnon-perturbation vehicle state on an intentional driving path;calculating a steering signal reference value based on thenon-perturbation vehicle state; comparing the steering signal referencevalue with an instantaneous steering signal value to determine anydifference; and if a difference exceeds a predetermined error-limitvalue determining the driver input is a reaction to an unexpecteddeviation from the intentional driving path.
 11. The method of claim 10including calculating the steering signal reference value using aninverse vehicle model for a steering angle corresponding to thedetermined instantaneous non-perturbation vehicle state.
 12. The methodof claim 10 including calculating the steering signal reference valueusing an inverse model for a steering velocity corresponding to thedetermined instantaneous non-perturbation vehicle state.
 13. The methodof claim 10 including establishing a predetermined bandwidth for anabsolute value of an instantaneous steering-angle value; determiningwhether the absolute value of the instantaneous steering-angle valuelies outside a respectively corresponding, predetermined bandwidth; andbased on the absolute value lying outside the predetermined bandwidthdetermining the driver input is a reaction to an unexpected deviation ofthe motor vehicle from the intentional driving path.
 14. The method ofclaim 10 including establishing predetermined bandwidths for an absolutevalue of an instantaneous steering-velocity value; determining whetherthe absolute value of the instantaneous steering-velocity value liesoutside the predetermined bandwidth; and based on the absolute valuelying outside the predetermined bandwidth determining the driver inputis a reaction to an unexpected deviation of the motor vehicle from theintentional driving path.
 15. The method of claim 10 wherein at leastone driver-assistance system is deactivated upon determining driverinput is a reaction to unexpected deviations of the motor vehicle fromthe desired driving path.
 16. The method of claim 10 includingactivation of a driver-assistance countersteering system supportingdriver input to unexpected deviations from the desired driving path tomaintain the vehicle on the desired driving path.
 17. The method ofclaim 10 wherein calculating a steering signal reference value based onthe non-perturbation vehicle state includes using an input signal baseon a vehicle operating parameter selected from the following group:longitudinal acceleration of the vehicle along its longitudinal axis;transverse acceleration of the vehicle along a transverse axis of thevehicle; vertical acceleration of the vehicle along a vertical axis ofthe vehicle; longitudinal velocity; transverse velocity; verticalvelocity; yaw velocity; sway velocity; roll velocity; yaw acceleration;sway acceleration; roll acceleration; wheel speeds; and wheelaccelerations of individual wheels or of several wheels of the motorvehicle.
 18. The method of claim 10 wherein calculating a steeringsignal reference value based on the non-perturbation vehicle stateincludes using a temporally last value of the steering signal referencevalue relating to a steering value corresponding to an instantaneousnon-perturbation vehicle state on an intentional driving path assteering signal reference value for the comparison with theinstantaneous steering signal value.
 19. The method of claim 10including determining the instantaneous steering signal value based on avehicle operating parameter selected from the following group: wheelspeeds and/or wheel accelerations of individual wheels or several wheelsof the motor vehicle; position of the steering wheel or the steeringcolumn, ascertained by a steering sensor, angular velocity of thesteering wheel about the steering axis of the steering column; andposition of at least one steering wheel with respect to the steeringangle.